Seagate ST251 - Access Time Definition and Timing; Step Pulse Period and Seek Method

1.2 ACCESS TIME DEFINITION AND TIMING
Access time is defined as the time from the leading edge of the first
step pulse received to
Seek Complete (including settling). All seek
times are
true statistical averages and are calculated with a step pulse
period of
10 psec. at nominal power and temperature.
Track-to-Track:
Average:
Full-Stroke:
Average Latency:
8 msec. max.
40 msec. max.
95 msec. max.
8.33 msec.
1.3 STEP PULSE PERIOD AND SEEK METHOD
The step signal is a 2psec. minimum width pulse which initiates read/
write head motion. The step pulse period determines the access
method. The number of pulses determines the seek length. The step
pulse period must
be between 3/lsec. and 200/lsec.
Step pulses may be lost at periods greater than 200jJsec. For additional
information on step pulses and seek methods consult the Seagate
ST412
Interface Manual.
1-2 ST251 1251 RI277R Product Manual, Rev.A